CPCT CPCT Fiber Optic Cabling & Termination 2 — Questions and Answers
Question 1: What is the acceptable insertion loss limit per mated fiber optic connector pair per TIA-568?
- 0.75 dB (Correct answer)
- 2.0 dB
- 0.1 dB
- 3.5 dB
Correct answer: 0.75 dB
TIA-568 specifies a maximum insertion loss of 0.75 dB per mated connector pair for field-terminated fiber optic connectors.
Question 2: Which type of fiber optic splice offers the lowest typical loss and the most permanent connection?
- Fusion splice (Correct answer)
- Mechanical splice
- Adhesive splice
- Crimp splice
Correct answer: Fusion splice
Fusion splicing uses an electric arc to melt and join two fiber ends, producing losses typically below 0.1 dB and a permanent, low-reflection joint.
Question 3: OM3 multimode fiber is characterized by which core diameter and minimum modal bandwidth?
- 50µm core, 2000 MHz·km at 850nm (Correct answer)
- 62.5µm core, 160 MHz·km at 850nm
- 9µm core, unlimited bandwidth
- 50µm core, 500 MHz·km at 850nm
Correct answer: 50µm core, 2000 MHz·km at 850nm
OM3 laser-optimized multimode fiber has a 50µm core and a minimum overfilled launch bandwidth of 2000 MHz·km at 850nm, supporting 10GbE up to 300m.
Question 4: What is the purpose of an index-matching gel used during fiber optic mechanical splicing?
- To fill the air gap between fiber ends and reduce back reflection and insertion loss (Correct answer)
- To protect the fiber from moisture
- To increase the physical strength of the splice
- To strip the fiber coating before splicing
Correct answer: To fill the air gap between fiber ends and reduce back reflection and insertion loss
Index-matching gel has a refractive index close to the fiber core, filling microscopic gaps between fiber ends to minimize signal loss and reflection at the splice.
Question 5: When installing fiber optic cable in a conduit shared with copper cabling, which standard practice must be followed?
- Fiber and copper must be separated into different conduits because pulling tension and bend radius requirements differ (Correct answer)
- Fiber may always share conduit with any copper cable without restriction
- Fiber must always be installed first before copper
- No special precautions are needed since fiber is immune to EMI
Correct answer: Fiber and copper must be separated into different conduits because pulling tension and bend radius requirements differ
TIA-568 recommends separate conduits for fiber and copper because fiber's lower pull-tension limits and bend radius requirements can be violated when sharing conduit with stiffer copper cables.
Question 6: What is the standard color code for OM4 multimode fiber optic cable jacket per TIA-598?
- Erika violet (magenta) (Correct answer)
- Aqua
- Yellow
- Orange
Correct answer: Erika violet (magenta)
TIA-598 designates erika violet (magenta/purple) as the jacket color for OM4 50µm laser-optimized multimode fiber to distinguish it from OM3 aqua fiber.
CPCT CPCT Fiber Optic Cabling & Termination 2
What is the acceptable insertion loss limit per mated fiber optic connector pair per TIA-568?